Would you consider yourself an endurance athlete?
If you answered yes, it’s likely you’ve heard of some, or all of these terms:
- anaerobic threshold (AT)
- lactate threshold (LT)
- ventilatory threshold (VT)
- maximum lactate steady state (MLSS)
- onset of blood lactate accumulation (OBLA)
The term Anaerobic Threshold (AT) is perhaps one of the most confusing terms in endurance sports training. The primary reason for using measurements to infer AT is because it is more of a ‘concept’ than an established metric. The term ‘anaerobic’ is often used in relation to any high intensity exercise level. Big deal you say… it’s just semantics. Maybe, but the reality is that words matter and in respect to exercising at a high intensity level, there is better and more accurate terminology to use.
The term anaerobic is often used erroneously to denote exercise that occurs ‘without oxygen.’ Exercise that uses oxygen is referred to as ‘aerobic.’ Therefore, the common thought process regarding aerobic and anaerobic exercise is that once an individual reaches their AT, their body “switches” from using oxygen (aerobic) to the anaerobic energy systems to provide energy.
This is incorrect. In actuality, oxygen is present at all times during intense exercise. Anaerobic energy systems supplement the aerobic system to meet the increased energy demands.
The term, Anaerobic Threshold was created by Wasserman and McIlroy in 1964 as a way to identify a safe, sub-maximal intensity for cardiac patients to exercise at. The premise of their Anaerobic Threshold Theory was that blood lactate accumulation was the result of poor oxygen levels – NOT that an individual had switched over from using oxygen to using anaerobic energy systems to provide energy.
Lactate and Ventilatory Threshold
So is AT real? Depends. It all comes down to how you define it. However, for all intents and purposes, it is advised that one’s lactate threshold (LT) is a better metric than AT, primarily because it can be quantitatively measured and therefore it is not a concept but an actual metric.
Lactate threshold is highly correlated to ventilatory threshold (VT). VT is a fancy term used to denote when an individual’s breathing becomes labored. This is commonly assessed via the Talk Test. During the test, one’s VT is reached when the subject can no longer recite a phrase during the test. In other words, they cannot hold a conversation. During exercise, one’s ventilation rate rises in direct proportion to the exercise intensity, until about 50-75% of one’s VO2 Max. After this point, the ventilation rate rises exponentially. This inflection point is representative of one’s VT.
We’re not trying to be the word police here but as noted above, words matter and there are enough things to be confused about in the world of exercise science without adding one more thing to the pile.
Therefore, it is advised to use terms that are quantifiable or at least an actual ‘thing’ versus a concept.
Rick Prince is the founder/director of United Endurance Sports Coaching Academy (UESCA), a science-based endurance sports education company. UESCA educates and certifies running and triathlon coaches (cycling and ultrarunning coming soon!) worldwide on a 100% online platform.
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